What is acne? Acne is a common skin condition that happens when hair follicles under the skin become clogged. Oil and dead skin cells plug the pores, and outbreaks of lesions (often called pimples or zits) can happen. Most often, the outbreaks occur on the face but can also appear on the back, chest, and shoulders. For most people, acne tends to go away by the time they reach their thirties, but some people in their forties and fifties continue to have this skin problem.
What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.
What is reactive arthritis? Reactive arthritis happens when an infection causes joint pain and swelling. A bacterial infection in the digestive or urinary tract or the genitals usually triggers the condition, but arthritis symptoms typically do not start until a few weeks after you have recovered from the infection. The most common features of reactive arthritis are inflammation of the joints (especially the knees and ankles), eyes, and urinary tract, but not everyone gets all three, or they might not happen at the same time.
What is Sjögren’s syndrome? Sjögren’s syndrome is a chronic (long-lasting) disorder that happens when the immune system attacks the glands that make moisture in the eyes, mouth, and other parts of the body. The main symptoms are dry eyes and mouth, but the disorder may affect other parts of the body. Many people with Sjogren’s syndrome say they feel tired often (fatigue). They also may have joint and muscle pain. In addition, the disease can damage the lungs, kidneys, and nervous system.
What is osteonecrosis? Your bones are made up of living cells that need a blood supply to stay healthy. In osteonecrosis, blood flow to part of a bone is reduced. This causes death of bone tissue, and the bone can eventually break down and the joint will collapse. Osteonecrosis can happen to any bone, but most often it develops in the ends of long bones, such as the: Thigh bone. Upper arm bone. Less often, the bones of the elbows, ankles, feet, wrists, and hands are affected. When the disease involves part of a bone in a joint, it can
What is Raynaud’s phenomenon? Raynaud’s phenomenon is a condition that causes the blood vessels in the hands and feet to narrow, decreasing blood flow. When this happens, parts of the body—usually the fingers and toes—become cold and numb, and change color (usually, to white or blue). An attack usually happens from exposure to cold or stress.
What is epidermolysis bullosa? Epidermolysis bullosa is a group of rare diseases that cause fragile skin that leads to blisters and tearing. Tears, sores, and blisters in the skin happen when something rubs or bumps the skin. They can appear anywhere on the body. In severe cases, blisters may also develop inside the body. The symptoms of the disease usually begin at birth or during infancy and range from mild to severe.
What is fibrous dysplasia? Fibrous dysplasia happens when abnormal fibrous (scar-like) tissue replaces healthy bone. The fibrous tissue weakens the bone over time, which can lead to: Broken bones. Bones that are misshapen (bowed or crooked). The disease can affect any bone in the body. Some people have no symptoms or only a few symptoms. Other people may have more symptoms. Although there is no cure for fibrous dysplasia, treatments may help to lessen pain, and physical therapy may help strengthen muscle and improve movement.
What is scleroderma? Scleroderma is an autoimmune connective tissue and rheumatic disease that causes inflammation in the skin and other areas of the body. This inflammation leads to patches of tight, hard skin. Scleroderma involves many systems in your body. A connective tissue disease is one that affects tissues such as skin, tendons, and cartilage. There are two major types of scleroderma: Localized scleroderma only affects the skin and the structures directly under the skin. Systemic scleroderma, also called systemic sclerosis, affects many systems in the body. This is the more serious type of scleroderma and can damage your blood